# Is there a built-in Python function to generate 100 numbers from 0 to 1?

## Question:

I am looking for something like `range`, but one that will allow me to specify the start and the end value, along with how many numbers I need in the collection which I want to use in a similar fashion `range` is used in `for loops`.

Python doesn’t have a floating point range function but you can simulate one easily with a list comprehension:

``````>>> lo = 2.0
>>> hi = 12.0
>>> n = 20
>>> [(hi - lo) / n * i + lo for i in range(n)]
[2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5]
``````

Note, in numeric applications, people typically want to include both endpoints rather than have a half-open interval like Python’s built-in range() function. If you need both end-points you can easily add that by changing `range(n)` to `range(n+1)`.

Also, consider using numpy which has tools like arange() and linspace() already built in.

You can still use `range`, you know. You just need to start out big, then divide:

``````for x in range(100):
print x/100.0
``````

If you want to include the endpoint:

``````for x in range(101):
print x/100.0
``````

There is a special function in numpy to do this: `linspace`. Ofcourse you will have to install numpy first. You can find more about it here.

No, there is no built-in function to do what you want. But, you can always define your own `range`:

``````def my_range(start, end, how_many):
incr = float(end - start)/how_many
return [start + i*incr for i in range(how_many)]
``````

And you can using in a for-loop in the same way you would use `range`:

``````>>> for i in my_range(0, 1, 10):
...     print i
...
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
``````

EDIT: If you want both `start` and `end` to be part of the result, your `my_range` function would be:

``````def my_range(start, end, how_many):
incr = float(end - start)/(how_many - 1)
return [start + i*incr for i in range(how_many-1)] + [end]
``````

``````>>> for i in my_range(0, 1, 10):
...   print i
...
0.0
0.111111111111
0.222222222222
0.333333333333
0.444444444444
0.555555555556
0.666666666667
0.777777777778
0.888888888889
1
``````
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